Boomer the dog has a bone to pick with the world. He wants to be accepted for his doggie lifestyle.

Born Gary Matthews, the retired technology worker and a self-confessed "nerd" thinks he is a dog. The 48-year-old wears a dog collar, eats dog food from a bowl — his favorite is Pedigree – and loves milk bones and dog cookies.

"I don't eat dog food every day," Matthews told ABCNews.com "It's a special thing for me to do once in awhile to get closer to feeling like a canine. I eat the canned kind. It's not bad -- it tastes OK. I eat regular human food, too, like pizza."

But he has the most fun wearing his dog suit, code-named "Papey," because he made it from shredded paper. He wanders around the streets of his hometown Pittsburgh, barking at cars and digging holes in the backyard.

"When I go out, I get the feeling and I wave to people as a dog," he said. "I go to local festivals because kids like the costume. That's my way of reaching out to people and spreading the word that I can be myself in life. They see that you can have fun in adulthood. But I am kind of a loner dog."

"Sometimes I sleep in my dog house, which is up in the attic -- I built it myself," said Matthews. "It's made out of wood and I can take it apart and move it. I go up there and read a book. It has a little night light and is like a club house."

Courtesy of Gary Matthews

PHOTO: Gary Matthews loved dogs as a child.

The mild-mannered and seemingly rational man even has a telephone answering machine that barks. His emails say "pawed" instead of, "said." and he runs a website Boomer the Dog, and a podcast.

Matthews said he got the name from the television series "Here's Boomer," which ran from 1979 to 1982 about a stray dog.

But his obsession started long before that, with a dog named Pongo from Disney's "101 Dalmatians" and a series of Disney movies that began in 1959 called "The Shaggy Dog."

"Sometimes, I would bark or maybe get into a big box and peek out with my paws over the side of it like a dog would do." -- Gary Matthews

"It's been a long process," he said. "It started when I saw "The Shaggy DA" in 1976 when I was 11 years old. I went with my Dad to see it. I was already a dog freak and collecting pictures of dogs. I saw this movie and there was something different about it -- the dad transforms into a big sheep dog. I had never seen that idea played out anywhere."

"I started playing dog and getting into it," said Matthews. "It was like a kid thing. Sometimes, I would bark or maybe get into a big box and peek out with my paws over the side of it like a dog would do. In a couple of years, I really got into it. ... Maybe I was looking for a personality to have."

He would draw dogs and watch every TV show about dogs. His father, a pharmacist, became less supportive of Matthew's growing canine identity and worried about his future.

As Matthews grew older and was "getting out in the world," he said he was drawn to the furry white television mutt, Boomer – a "nerd type of dog" -- and took his name.

The word anthropomorphism comes from the Greek words "anthros" for human and "morph" for form and refers to the attributing human qualities and emotions to nonhumans.

Matthews said he has never been in trouble with the law and is not seeing a psychiatrist or taking any kind of medications for mental illness. Money is not a problem. When his parents died, he inherited their house and they left him a trust fund to live on.